29.4.3.6 Frame Interaction Parameters

These parameters supply forms of interactions between different frames.

parent-frame

If non-nil, this means that this frame is a child frame
(see Child Frames), and this parameter specifies its parent frame.
If nil, this means that this frame is a normal, top-level frame.

delete-before

If non-nil, this parameter specifies another frame whose deletion
will automatically trigger the deletion of this frame. See Deleting Frames.

mouse-wheel-frame

If non-nil, this parameter specifies the frame whose windows will
be scrolled whenever the mouse wheel is scrolled with the mouse pointer
hovering over this frame, see Mouse Commands.

no-other-frame

If this is non-nil, then this frame is not eligible as candidate
for the functions next-frame, previous-frame
(see Finding All Frames) and other-frame, see Frame Commands.

auto-hide-function

When this parameter specifies a function, that function will be called
instead of the function specified by the variable
frame-auto-hide-function when quitting the frame's only window
(see Quitting Windows) and there are other frames left.

minibuffer-exit

When this parameter is non-nil, Emacs will by default make this
frame invisible whenever the minibuffer (see Minibuffers) is exited.
Alternatively, it can specify the functions iconify-frame and
delete-frame. This parameter is useful to make a child frame
disappear automatically (similar to how Emacs deals with a window) when
exiting the minibuffer.

keep-ratio

This parameter is currently meaningful for child frames (see Child Frames) only. If it is non-nil, then Emacs will try to keep the
frame's size (width and height) ratios (see Size Parameters) as well
as its left and right position ratios (see Position Parameters)
unaltered whenever its parent frame is resized.

If the value of this parameter is nil, the frame's position and
size remain unaltered when the parent frame is resized, so the position
and size ratios may change. If the value of this parameter is t,
Emacs will try to preserve the frame's size and position ratios, hence
the frame's size and position relative to its parent frame may change.

More individual control is possible by using a cons cell: In that case
the frame's width ratio is preserved if the car of the cell is
either t or width-only. The height ratio is preserved if
the car of the cell is either t or height-only. The
left position ratio is preserved if the cdr of the cell is either
t or left-only. The top position ratio is preserved if
the cdr of the cell is either t or top-only.